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/*++
/* NAME
/* bounce_warn_service 3
/* SUMMARY
/* send non-delivery report to sender, server side
/* SYNOPSIS
/* #include "bounce_service.h"
/*
/* int bounce_warn_service(flags, service, queue_name, queue_id,
/* encoding, smtputf8, sender, envid,
/* dsn_ret, templates)
/* int flags;
/* char *service;
/* char *queue_name;
/* char *queue_id;
/* char *encoding;
/* int smtputf8;
/* char *sender;
/* char *envid;
/* int dsn_ret;
/* BOUNCE_TEMPLATES *ts;
/* DESCRIPTION
/* This module implements the server side of the bounce_warn()
/* (send delay notice) request. The logfile
/* is not removed, and a warning is sent instead of a bounce.
/*
/* When a message bounces, a full copy is sent to the originator,
/* and an optional copy of the diagnostics with message headers is
/* sent to the postmaster. The result is non-zero when the operation
/* should be tried again.
/*
/* When a bounce is sent, the sender address is the empty
/* address. When a bounce bounces, an optional double bounce
/* with the entire undeliverable mail is sent to the postmaster,
/* with as sender address the double bounce address.
/* DIAGNOSTICS
/* Fatal error: error opening existing file.
/* BUGS
/* SEE ALSO
/* bounce(3) basic bounce service client interface
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
/* Utility library. */
#include <msg.h>
#include <vstream.h>
#include <name_mask.h>
#include <stringops.h>
/* Global library. */
#include <mail_params.h>
#include <mail_queue.h>
#include <post_mail.h>
#include <mail_addr.h>
#include <mail_error.h>
#include <dsn_mask.h>
#include <rec_type.h>
/* Application-specific. */
#include "bounce_service.h"
#define STR vstring_str
/* bounce_warn_service - send a delayed mail notice */
int bounce_warn_service(int unused_flags, char *service, char *queue_name,
char *queue_id, char *encoding,
int smtputf8, char *recipient,
char *dsn_envid, int dsn_ret,
BOUNCE_TEMPLATES *ts)
{
BOUNCE_INFO *bounce_info;
int bounce_status = 1;
int postmaster_status = 1;
VSTREAM *bounce;
int notify_mask = name_mask(VAR_NOTIFY_CLASSES, mail_error_masks,
var_notify_classes);
VSTRING *new_id = vstring_alloc(10);
char *postmaster;
int count;
/*
* Initialize. Open queue file, bounce log, etc.
*
* XXX DSN This service produces RFC 3464-style "delayed mail" reports from
* information in the defer logfile. That same file is used for three
* different types of report:
*
* a) On-demand reports of all delayed deliveries by the mailq(1) command.
* This reports all recipients that have a transient delivery error.
*
* b) RFC 3464-style "delayed mail" notifications by the defer(8) service.
* This reports to the sender all recipients that have no DSN NOTIFY
* information (compatibility) and all recipients that have DSN
* NOTIFY=DELAY; this reports to postmaster all recipients, subject to
* notify_classes restrictions.
*
* c) RFC 3464-style bounce reports by the bounce(8) service when mail is
* too old. This reports to the sender all recipients that have no DSN
* NOTIFY information (compatibility) and all recipients that have DSN
* NOTIFY=FAILURE; this reports to postmaster all recipients, subject to
* notify_classes restrictions.
*/
bounce_info = bounce_mail_init(service, queue_name, queue_id,
encoding, smtputf8, dsn_envid, ts->delay);
#define NULL_SENDER MAIL_ADDR_EMPTY /* special address */
#define NULL_TRACE_FLAGS 0
/*
* The choice of sender address depends on the recipient address. For a
* single bounce (a non-delivery notification to the message originator),
* the sender address is the empty string. For a double bounce (typically
* a failed single bounce, or a postmaster notification that was produced
* by any of the mail processes) the sender address is defined by the
* var_double_bounce_sender configuration variable. When a double bounce
* cannot be delivered, the queue manager blackholes the resulting triple
* bounce message.
*/
/*
* Double bounce failed. Never send a triple bounce.
*
* However, this does not prevent double bounces from bouncing on other
* systems. In order to cope with this, either the queue manager must
* recognize the double-bounce recipient address and discard mail, or
* every delivery agent must recognize the double-bounce sender address
* and substitute something else so mail does not come back at us.
*/
if (strcasecmp_utf8(recipient, mail_addr_double_bounce()) == 0) {
msg_warn("%s: undeliverable postmaster notification discarded",
queue_id);
bounce_status = 0;
}
/*
* Single bounce failed. Optionally send a double bounce to postmaster,
* subject to notify_classes restrictions.
*/
#define ANY_BOUNCE (MAIL_ERROR_2BOUNCE | MAIL_ERROR_BOUNCE)
#define SEND_POSTMASTER_DELAY_NOTICE (notify_mask & MAIL_ERROR_DELAY)
else if (*recipient == 0) {
if (!SEND_POSTMASTER_DELAY_NOTICE) {
bounce_status = 0;
} else {
postmaster = var_delay_rcpt;
if ((bounce = post_mail_fopen_nowait(mail_addr_double_bounce(),
postmaster,
MAIL_SRC_MASK_BOUNCE,
NULL_TRACE_FLAGS,
smtputf8,
new_id)) != 0) {
/*
* Double bounce to Postmaster. This is the last opportunity
* for this message to be delivered. Send the text with
* reason for the bounce, and the headers of the original
* message. Don't bother sending the boiler-plate text.
*/
count = -1;
if (!bounce_header(bounce, bounce_info, postmaster,
POSTMASTER_COPY)
&& (count = bounce_diagnostic_log(bounce, bounce_info,
DSN_NOTIFY_OVERRIDE)) > 0
&& bounce_header_dsn(bounce, bounce_info) == 0
&& bounce_diagnostic_dsn(bounce, bounce_info,
DSN_NOTIFY_OVERRIDE) > 0) {
bounce_original(bounce, bounce_info, DSN_RET_FULL);
bounce_status = post_mail_fclose(bounce);
if (bounce_status == 0)
msg_info("%s: postmaster delay notification: %s",
queue_id, STR(new_id));
} else {
(void) vstream_fclose(bounce);
if (count == 0)
bounce_status = 0;
}
}
}
}
/*
* Non-bounce failed. Send a single bounce, subject to DSN NOTIFY
* restrictions.
*/
else {
if ((bounce = post_mail_fopen_nowait(NULL_SENDER, recipient,
MAIL_SRC_MASK_BOUNCE,
NULL_TRACE_FLAGS,
smtputf8,
new_id)) != 0) {
/*
* Send the bounce message header, some boilerplate text that
* pretends that we are a polite mail system, the text with
* reason for the bounce, and a copy of the original message.
*/
count = -1;
if (bounce_header(bounce, bounce_info, recipient,
NO_POSTMASTER_COPY) == 0
&& bounce_boilerplate(bounce, bounce_info) == 0
&& (count = bounce_diagnostic_log(bounce, bounce_info,
DSN_NOTIFY_DELAY)) > 0
&& bounce_header_dsn(bounce, bounce_info) == 0
&& bounce_diagnostic_dsn(bounce, bounce_info,
DSN_NOTIFY_DELAY) > 0) {
bounce_original(bounce, bounce_info, DSN_RET_HDRS);
bounce_status = post_mail_fclose(bounce);
if (bounce_status == 0)
msg_info("%s: sender delay notification: %s",
queue_id, STR(new_id));
} else {
(void) vstream_fclose(bounce);
if (count == 0)
bounce_status = 0;
}
}
/*
* Optionally send a postmaster notice, subject to notify_classes
* restrictions.
*
* This postmaster notice is not critical, so if it fails don't
* retransmit the bounce that we just generated, just log a warning.
*/
if (bounce_status == 0 && SEND_POSTMASTER_DELAY_NOTICE
&& strcasecmp_utf8(recipient, mail_addr_double_bounce()) != 0) {
/*
* Send the text with reason for the bounce, and the headers of
* the original message. Don't bother sending the boiler-plate
* text. This postmaster notice is not critical, so if it fails
* don't retransmit the bounce that we just generated, just log a
* warning.
*/
postmaster = var_delay_rcpt;
if ((bounce = post_mail_fopen_nowait(mail_addr_double_bounce(),
postmaster,
MAIL_SRC_MASK_BOUNCE,
NULL_TRACE_FLAGS,
smtputf8,
new_id)) != 0) {
count = -1;
if (bounce_header(bounce, bounce_info, postmaster,
POSTMASTER_COPY) == 0
&& (count = bounce_diagnostic_log(bounce, bounce_info,
DSN_NOTIFY_OVERRIDE)) > 0
&& bounce_header_dsn(bounce, bounce_info) == 0
&& bounce_diagnostic_dsn(bounce, bounce_info,
DSN_NOTIFY_OVERRIDE) > 0) {
bounce_original(bounce, bounce_info, DSN_RET_HDRS);
postmaster_status = post_mail_fclose(bounce);
if (postmaster_status == 0)
msg_info("%s: postmaster delay notification: %s",
queue_id, STR(new_id));
} else {
(void) vstream_fclose(bounce);
if (count == 0)
postmaster_status = 0;
}
}
if (postmaster_status)
msg_warn("%s: postmaster notice failed while warning %s",
queue_id, recipient);
}
}
/*
* Cleanup.
*/
bounce_mail_free(bounce_info);
vstring_free(new_id);
return (bounce_status);
}
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